The field of the present invention relates to skeleton frame chassis used for overland transport of shipping containers. More particularly, the present invention relates to an adjustable chassis used to transport shipping containers having different configurations.
Shipping or freight containers are often used for transporting goods by ship, rail and overland trucking. These containers are constructed in several different sizes and configurations often according to international standards. For overland trucking, the container is positioned on a chassis, with the chassis coupled to a tractor, truck, or other suitable towing vehicle. Generally the chassis couples to a fifth-wheel on the tractor. To accommodate overland trucking by chassis, most shipping containers have a tunnel located in a front bottom portion of the container. The tunnel is designed to extend over a forward section of the chassis. This forward section is generally referred to as the gooseneck section. The chassis gooseneck section is generally higher than the chassis rear portion because the kingpin that attaches the chassis to the tractor fifth wheel is located under the gooseneck. The container tunnel is designed to accommodate the higher gooseneck section so that the overall height of the container, as measured from the ground to the top of the container, stays within Federal highway transportation standards.
Today, there are generally two types of shipping containers in widespread use. The xe2x80x9cstandardxe2x80x9d shipping container has a tunnel depth of about 4 xc2xe inches and a more recent design, sometimes referred to as a xe2x80x9cHigh-Cubexe2x80x9d container, has a shallower tunnel depth of about 3 xc2xc inches. The High-Cube container has a greater storage area than the standard container, permitting transportation of more goods. However, a High-Cube container placed on a chassis designed to fit a standard container will exceed Federal transportation height standards, because the top of the container is now about 1 xc2xd inches higher than allowed. This has forced transport companies to purchase and operate two different chassis, one configured for High-Cube containers and a second chassis configured for standard containers.
Variable, or convertible chassis have been developed in an effort to avoid the substantial logistical and financial expenditures associated with matching specific freight containers to specific chassis. These convertible chassis generally have variable height gooseneck supports made of moveable sections that can be configured to accommodate either type of container. However, these variable chassis have several shortcomings. For example, the conversion procedure necessary to covert the chassis from one configuration to the other requires the use of tools and considerable human effort, decreasing transportation efficiency and causing operator injuries. Because the moveable sections of the chassis are difficult to adjust from one configuration to another, operators sometimes transport a container with the chassis configured for a different type of container, resulting in a dangerous operating condition.
Another disadvantage is the moveable sections of the chassis do not extend along the entire length of the gooseneck. This adds stress to the container because only parts of the tunnel floor are supported by the gooseneck rails, causing deformation of the floor and subsequent fatigue failure of over-stressed containers. Full-length supports are not employed for a number of reasons, including the complexity of packaging the supports within the gooseneck, and the difficulty of designing a system that can easily rearrange full-length supports from one configuration to the other. This adds stress to the container because only parts of the tunnel are supported by the gooseneck rails, causing deformation of the container floor and subsequent fatigue failure of over-stressed containers.
Therefore, there exists a need for a variable height gooseneck chassis that can safely and efficiently accommodate containers having different tunnel heights.
In order to overcome the deficiencies with known, conventional shipping containers, a convertible chassis is provided. Briefly, the convertible chassis includes translation members coupled to the chassis that cooperate with conversion members. The conversion members are configured to be shifted by the translation members between a stored portion and a deployed position.
More specifically, one embodiment of the convertible chassis invention employs pivoting conversion members that are also pivotally coupled to the chassis. The conversion members are configured to be easily shiftable from a storage position between the chassis gooseneck frame members to a deployed position proximate to the chassis gooseneck frame members.
The convertible chassis of the present invention affords its users with a number of distinct advantages. First, unlike prior adjustable gooseneck chassis, the adjustable support sections of the present invention extend substantially along the entire length of the gooseneck frame members, thereby supporting the container tunnel floor. In addition, adjustment of the chassis from a High-Cube container configuration to a standard container configuration can be quickly accomplished by hand, without the use of any tools. Further, a disclosed embodiment of the present invention can be installed on existing High-Cube chassis, removing the need to operate and maintain specific chassis for specific freight containers.